In silver halide photographic photosensitive materials (hereinafter also referred to simply as “photosensitive material”) for subtractive color photography, a color image is formed by dyes of three primary colors of yellow, magenta, and cyan. In the color photography that uses current p-phenylenediamine-series color-developing agents, acylacetanilide-series compounds are used as a yellow coupler. However, the hue of yellow dyes obtained from these yellow couplers is reddish, due to an inferior sharpness of a peak of the absorption curve at the longer wavelength side (that is, on the absorption curve, the peak in interest has subsidiary absorption at its foot portion at the longer wavelength side), and it is difficult to obtain a yellow hue with high purity. Further, the above-mentioned dyes are sometimes easily decomposed under conditions of high temperature and high humidity, or of irradiation of light, and thus they have insufficient image storability after development processing. Further, because the molecular extinction coefficient of the dye is low, large quantities of the coupler and silver halide are needed to obtain a desired color density, which results in an increase in the film thickness of the photosensitive material. Such increased film thickness sometimes reduces sharpness of the dye image, and also becomes a serious hindrance to the rapid processing that has been strongly utilized in recent years. In this situation, improvement of these performances has been desired.
In order to solve these problems, improvement of acyl groups and anilido groups were proposed on the couplers. Recently, as improved couplers of the conventional acylacetanilide-series couplers, there were proposed, for example, 1-alkylcyclopropanecarbonyl acetanilide-series compounds, cyclomalondiamide-type couplers, pyrrole-2- or 3-yl- or indole-2- or 3-yl-carbonylacetanilide-series couplers. The dyes formed from these couplers were improved in terms of both hue and molecular extinction coefficient of dyes formed, compared with the conventional ones. However, they are not satisfactory in image storability still. Further, owing to their complicated chemical structure, the synthesis route became longer, and consequently cost of the couplers became higher, causing a practical problem. In addition, U.S. Pat. No. 3,841,880, JP-A-52-82423 (“JP-A” means unexamined published Japanese patent application) and JP-A-2-28645 propose acetic ester-series and acetanilide-series couplers to which 1,2,4-benzothiadiazine-1,1-dioxide is bonded. However, these couplers are low in color-forming property, and they are inferior in sharpness of a peak of the absorption curve owing to the subsidiary absorption at the foot portion on the longer wavelength side. European Patent Publication No. 1246006A discloses couplers that have improved color-developing property and bottom definition of the absorption in the longer wavelength side of the aforementioned acetic ester-series and acetic anilide-series couplers to which 1,2,4-benzothiadiazine-1,1-dioxide is bonded, as described in U.S. Pat. No. 3,841,880, JP-A-52-82423 and JP-A-2-28645. These couplers described in European Patent Publication No. 1246006A give dyes having high coloring property (color-forming property) and excellent absorption characteristics. However, dyes obtained from these couplers are insufficient in fastness to light at low-density areas, under conditions of storage at high temperature. As a situation in which a photograph is exposed to an ambient light under conditions of storage at high temperature, for example, a display in a commercial photo studio can be imagined. Further, because a low density of yellow is used in forming an image of a human face, the fastness of yellow in such a density region is important. In this situation, there is a demand for further improvement of the yellow image in the low-density region. The bisphenol compounds used in Examples of the above-mentioned European Patent Publication No. 1246006A are not always sufficient to improve the fastness to light under the above-described storage conditions. In particular, there has been known no effective means for improving photo stain. Therefore, further improvement has been desired.
Further, in the color photography using current p-phenylenediamine-series color-developing agents, as magenta dye-forming couplers (hereinafter sometimes referred to simply as “magenta coupler”), pyrazoloazole-series magenta couplers have been preferably employed, from the view points of absorption characteristics and fastness to light. Of these couplers, 1H-pyrazolo[1,5-b][1,2,4]triazole-series magenta couplers having a tertiary alkyl group in the 6-position, and a phenylene group in the 2-position, as described in JP-A-1-302249, give a dye image having excellent fastness to light and heat. However, the couplers that are specifically disclosed in the aforementioned JP-A-1-302249 have a sulfonamido group in the meta-position of the phenylene group in the 2-position. In the spectral absorption characteristics of dyes obtained from such couplers having a substituent in the meta-position of the phenylene group in the 2-position, it has been found that the absorption at the foot portion is large and broadens. In view of color reproduction, there has been a demand for further improvement in the spectral absorption characteristics of these dyes. Further, it has been found that a photosensitive material containing the above-said coupler has problems in storability after exposure of the photosensitive material to development, such as fluctuation of photographic performances. In addition, there is a demand for photosensitive materials having minimized fluctuation of photographic performances against changes in compositions of processing solutions. A major factor of the change in the composition of a processing solution is increased contamination and accumulation of components from other processing-solutions, during running processing or intermittent continuous processing with an automatic processor. This phenomenon is significant when a replenisher amount is reduced, thereby resulting in reduction of the replenishment rate of a tank solution, or when use is made of a processing solution that has a longer workable period. The above “contamination of other processing solutions” is caused by a splash of a nearby solution, or by so-called back contamination in which components of the solution directly after the development step are carried into a color-developing solution, by a conveying leader or belt, a hanger hanging down a film, and so on. When the photosensitive material containing the coupler described in the aforementioned JP-A-1-302249 is processed with a color-developing solution contaminated by a fixing agent, which is one of these accumulating contamination components, the fluctuation of its photographic properties is great. Accordingly, further improvement in fluctuation has been desired.
Further, it has been found that photosensitive materials containing a coupler having a methyl group in the ortho-position of the phenylene group in the 2-position of the coupler, which said coupler is described in JP-A-3-48845, also has a problem that the color-forming property is low, in addition to the above-mentioned problems. Accordingly, further improvement of these couplers has been desired.
To solve these problems, further studies in improving of couplers were made. Such couplers were disclosed, for example, in JP-A-6-43611 and JP-A-2001-242606. However, 1H-pyrazolo[1,5-b][1,2,4]triazole-series magenta couplers, including these couplers, do not give satisfactory fastness to light in low-density portions. In particular, the low-density portion of magenta is an important density area in reproducing an image of a human face.
Further, for color papers, processing by means of a mini-lab has become predominant in recent years. Mini-labs are required not only high finished quality and stability but also so-called rapid processing suitability meaning the ability to process a great number of photographic papers in a small installation area.
The particular bisphenol compounds that are used in the aforementioned JP-A-6-43611 have the problem that the said bisphenol compound itself acts as a competing compound to a coupler, resulting in a reduction of developed color density in rapid processing.
In view of this situation, development of technologies that realize high fastness to light in the low-density area and high developed color density even in rapid processing, has been desired.